In fact, being a mum means so much to her that she turned down a chance to co-star with husband James McAvoy in an adaptation of Irvine Welsh's Filth, to spend time with her son, two-year old Brendan.

According to actor John Sessions, Anne-Marie, who describes Brendan as "the most beautiful creature in the world", is not in the film because the couple were taking turns looking after the little one and it was her turn.

John who co-stars with James in Filth added: "He’s married a wonderful girl."

The adaptation of Irvine Welsh's novel, which also stars Jamie Bell and Jim Broadbent, will be released in cinemas in 2013.